By Julian Linden
EAST RUTHERFORD, New Jersey (Reuters) - The Green Bay Packers and San Francisco 49ers booked their spots in the National Football League (NFL) playoffs on Sunday with four weeks of the regular still to go.
The unbeaten Packers were gifted a place in the postseason even before their game against the New York Giants (6-6) kicked off when their NFC North division rivals, the Chicago Bears (7-5), were upset 10-3 by the Kansas City Chiefs (5-7).
The reigning Super Bowl champions then crowned their success by beating the Giants 38-35 in a thriller at Meadowlands Stadium that came down to the lazy play, stretching their winning streak to 12 games to remain on track for a rare perfect season.
The Packers would also wrap up the division if the Detroit Lions (7-4) lost to the New Orleans Saints (8-3) in Sunday's late game.
The 49ers (10-2) sealed their playoff berth and the NFC West division title with a 26-0 shutout over the struggling St. Louis Rams (2-10) while the battle for playoff spots in the AFC looked likely to go down to the wire with none of the teams able to break free of the pack.
Last year's Super Bowl runner-up, the Pittsburgh Steelers (9-3), posted a thumping 35-7 win over the Cincinnati Bengals (7-5) only to remain behind Baltimore (9-3) in the AFC North division after the Ravens beat the Cleveland Browns 24-10.
The Houston Texans (9-3) snuck past the Atlanta Falcons (7-5) to move two games clear in the AFC South while the New England Patriots (9-3) held off the winless Indianapolis Colts 31-24 to lead the AFC East by two but still not assured of anything.
The Denver Broncos (7-5), led by in-form quarterback Tim Tebow, rallied for a 35-32 win over the struggling Minnesota Vikings (2-10) after Matt Prater kicked a 23-yard field goal on the final play of the game to leapfrog Oakland (7-5) at the top of the AFC West standings after the Raiders fell 34-14 to the Miami Dolphins (4-8).
Green Bay quarterback Aaron Rodgers threw four touchdowns then Mason Crosby kicked a 30-yard field goal as time expired as the Packers survived a scare from a greatly-improved Giants team that suffered their fourth straight defeat to remain in danger of missing the postseason.
"This was the first step," said Rodgers. "Get in the playoffs, win the division, get a first-round bye, homefield advantage and hopefully go undefeated."
The 49ers showed why they have the best defense in the NFL as they booked their first playoff berth in nine years with Alex Smith throwing for two long touchdowns.
The Bears, already without quarterback Jay Cutler, suffered another blow during their surprise loss to the Chiefs when running back Matt Forte left the game with a right knee injury in the first half.
Pittsburgh quarterback Ben Roethlisberger threw a pair of touchdown passes while Rashard Mendenhall rushed for two more as the Steelers recorded their third straight win.
The Texans made it six wins on the trot, a record for the franchise, when Arian Foster scored the winning touchdown and rookie quarterback T.J. Yates celebrated his first NFL start with a win.
Another rookie, Cam Newton, set a NFL record for the most rushed touchdowns in a season by a quarterback when he scored three times in the Carolina Panthers' (4-8) dominating 38-19 victory over the Tampa Bay Buccaneers (4-8).
Newton took his total for rushed touchdowns for the season to 13, one more than the previous mark set by Steve Grogan in 1976.
Rob Gronkowski set a single-season record for touchdowns by a tight end in the Patriots' win over the Colts (0-12), the only remaining winless team this season.
Gronkowski scored twice to lift his season total to 14 touchdowns, eclipsing the previous record of 13 jointly held by Vernon Davis and Antonio Gates.
(Editing by Frank Pingue)